Haixin Gao,Qiang Fang,Yanfen Bai,Chunyue Hu,Howard H. Chou
Biosynthesis of 12-aminododecanoic acid (ADDA) directly from biomass-derived sugars would enable a more sustainable process for manufacturing the engineering polymer Nylon 12. ADDA biosynthesis is currently hindered by the cytotoxicity of dodecanoic acid (DDA) to growing cells, and the accumulation of the overoxidized byproduct dodecanedioic acid (DDDA). In this study, these challenges were addressed by engineering an autoinducible system to better control in vivo DDA synthesis without impacting growth, and deleting aldehyde dehydrogenases and oxidases to reduce DDDA accumulation. As a result, a one-step fermentation process was established to synthesize ADDA from glucose and cellobiose. Finally, batch fermentation achieved 1035 mg/L ADDA and 5% yield, which is the highest titer and yield accomplished directly from sugar to date. This research contributes to the mechanistic understanding of microbial DDA, ADDA, and DDDA synthesis, as well as the goal of developing more sustainable processes for nylon production.
Si-Ao Xin,Yanxiang Wang,Shanshan Xu,Yanying Zhu,Ziyi Xu,Yanru Yuan,Dong Zhang,Yingfan Li,Shaoao Hu
Powder coating, as a promising coating material, has attracted widespread attention due to its convenient construction and being a green option, promoting environmental protection. However, the existence of defects such as insufficient leveling and poor mechanical properties of the coating during the coating process limits the further expansion of its application fields. Therefore, for this article, powder coatings with high leveling performance were prepared by composite modification of nylon 12 (PA-12) resin with polyacrylates and ethylene-α-olefin copolymers (POE). The introduction of modified polyacrylates reduces the surface tension of nylon chains, enhancing melt flowability during curing and making the coating surface smooth. Furthermore, by introducing POE, the flexibility of the powder coating was improved, and its fracture elongation increased from 59% for pure PA-12 to a maximum of 234%. This study provides an effective method for the modification of nylon powder coatings and offers new insights into their use in high-performance coating applications.
危险品化学品经营许可证（带存储）